PPC: [Atomics] Remove Atomics code stubs; use TF ops

PPC: [Atomics] Remove Atomics code stubs; use TF ops

Port d412cfa26c18a6ef1f6c0e274ee51f3d834eab74

Original commit message:
    [Atomics] Remove Atomics code stubs; use TF ops

    Reland of (https://codereview.chromium.org/1891033002)

    This is a much cleaner solution, which won't require nearly as much
    architecture-specific code. Thanks bmeurer@!

R=binji@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=v8:4614
LOG=N

Committed: https://crrev.com/697c87414b775d10268339fcef3b1a58c186181d
Cr-Commit-Position: refs/heads/master@{#35631}

[JaideepBajwa, 2016-04-18 22:45:09]

PTAL

[MTBrandyberry, 2016-04-19 14:13:08]

https://codereview.chromium.org/1899033002/diff/1/src/compiler/ppc/code-gener...
File src/compiler/ppc/code-generator-ppc.cc (right):

https://codereview.chromium.org/1899033002/diff/1/src/compiler/ppc/code-gener...
src/compiler/ppc/code-generator-ppc.cc:681: MemOperand(i.InputRegister(0),
i.InputRegister(1))); \
If you want to support the non-indexed load form here, take a look at how other
paths contruct the MemOperand with i.MemoryOperand (see ASSEMBLE_LOAD_FLOAT for
an example).

https://codereview.chromium.org/1899033002/diff/1/src/compiler/ppc/code-gener...
src/compiler/ppc/code-generator-ppc.cc:686: __ lwsync();                        
                             \
Joran was going to get another opinion on correctness, but for now let's go with
the documented sequence
   [sync;  <load>; cmp; bc; isync]
implemented in the CL prior to this refactor.  See ASSEMBLE_ATOMIC_LOAD here:
https://codereview.chromium.org/1902433003/diff/20001/src/ppc/code-stubs-ppc.cc

[MTBrandyberry, 2016-04-19 15:24:35]

lgtm

[JaideepBajwa, 2016-04-19 16:30:18]

The CQ bit was checked by bjaideep@ca.ibm.com

[commit-bot: I haz the power, 2016-04-19 16:30:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1899033002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1899033002/20001

[commit-bot: I haz the power, 2016-04-19 16:53:40]

Committed patchset #2 (id:20001)

[nodir1, 2016-04-22 18:43:12]

Description was changed from

==========
PPC: [Atomics] Remove Atomics code stubs; use TF ops

Port d412cfa26c18a6ef1f6c0e274ee51f3d834eab74

Original commit message:
    [Atomics] Remove Atomics code stubs; use TF ops

    Reland of (https://codereview.chromium.org/1891033002)

    This is a much cleaner solution, which won't require nearly as much
    architecture-specific code. Thanks bmeurer@!

R=binji@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=v8:4614
LOG=N
==========

to

==========
PPC: [Atomics] Remove Atomics code stubs; use TF ops

Port d412cfa26c18a6ef1f6c0e274ee51f3d834eab74

Original commit message:
    [Atomics] Remove Atomics code stubs; use TF ops

    Reland of (https://codereview.chromium.org/1891033002)

    This is a much cleaner solution, which won't require nearly as much
    architecture-specific code. Thanks bmeurer@!

R=binji@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=v8:4614
LOG=N

Committed: https://crrev.com/697c87414b775d10268339fcef3b1a58c186181d
Cr-Commit-Position: refs/heads/master@{#35631}
==========

[nodir1, 2016-04-22 18:43:13]

Patchset 2 (id:??) landed as
https://crrev.com/697c87414b775d10268339fcef3b1a58c186181d
Cr-Commit-Position: refs/heads/master@{#35631}